A. Field of the Invention
The invention relates to artificial organs and glands and comprises an ultra filtering hybrid artificial organ or gland for providing a corrected physiological response to blood constituents in a rapid manner.
B. Prior Art
Increased activity in recent years has been devoted to developing artificial organs of various kinds. Much of the early effort has been devoted to developing organs which perform primarily mechanical functions, e.g., the heart. More recent activity has extended to the construction of organs which attempt to duplicate body physiology, e.g., dialysis devices and the like. This typically presents a more difficult problem than duplication of mechanical functions, due to the compexities of the physiologic system. An even greater level of difficulty is presented in the design and construction of devices which duplicate glandular functions, and progress in this area has been less rapid than in others.
Several devices which perform the function of the endocrine pancreas have been proposed. Aside from wholly artificial devices that depend on glucose sensors, algorithmic contollers, and refillable insulin reservoirs, attempts have been made to utilize natural pancreatic beta cells within an artificial structure as a form of protected and facilitated transplantation known as a hybrid artificial pancreas. Such devices include mechanisms for closely contacting the blood of a patient with this living glandular material, usually through a microporous membrane separating the two, so that the glandular material may respond to various constituents in the blood and exchange selected material therewith by simple diffusion, yet avoid rejection by host lymphocytes and antibodies that are too large to pass through the pores. In these devices, the glandular material actually adheres to the membranes and grows into and encroaches the pores resulting in proximity to the blood compartment improving diffusion back and forth across the membrane.
Such devices constitute an advance in the art but suffer the critical disadvantage, among others, that there is a significant time delay in the process of diffusion of various constituents, such as glucose and insulin, across the membrane despite the use of large membrane surface areas. This delay is undesirable to the extent that it departs from the normal tight physiological control and, in some cases, may present a risk to an individual dependent on such a device for rapid response to abnormal body conditions, i.e., a stressed diabetic relying on the device for production of insulin in response to acutely changing glucose levels in the blood. Additionally, this loose control of blood sugar may prevent the long-term tight control of diabetes necessary to prevent the complications of retinopathy and nephropathy, neuropathy, and accelerated vascular disease that all too often results in blindness, kidney failure, impotence, and premature heart attack.